The Wonder Under should work.
I use this method to affix Mariner's Compasses to the background.
For me, it's more of a way get the look of smooth edged needle-turn applique ....without the needle-turn part.
Use a smaller stitch when sewing the star lines on the interfacing and fabric, and when you turn it, gently poke the points - otherwise you'll go straight through the interfacing with the awl (or whatever you're using).
Maybe even go over the points once or twice to make sure the stitching is secure before you turn it inside out.
You can use a small zig-zag (or more of a satin stitch) to adhere it to the background - in matching or contrasting thread, depending on the look you're going for.
(Like I said above, I've always hand stitched it down).
Oh, yeah, and make sure that you've got the interface oriented correctly - fusible (dots) to right side of fabric to start.
Been there, done that.